Making a practical valleytronics device Two-dimensional materials with a hexagonal lattice, such as graphene, have two distinct “valleys” in their band structure. Researchers in the emerging field of valleytronics hope that these valley degrees of freedom can be exploited as information carriers, but making valleytronic devices is tricky. Li et al. created chiral valley Hall states on the boundary between oppositely gated regions of bilayer graphene. They then guided these so-called kink states through their sample using spatially modulated gating, demonstrating right and left turns, as well as a valley valve function. Science, this issue p. 1149 Spatially modulated gating of a bilayer graphene sample controls the propagation of chiral valley Hall currents. Developing alternative paradigms of electronics beyond silicon technology requires the exploration of fundamentally new physical mechanisms, such as the valley-specific phenomena in hexagonal two-dimensional materials. We realize ballistic valley Hall kink states in bilayer graphene and demonstrate gate-controlled current transmission in a four-kink router device. The operations of a waveguide, a valve, and a tunable electron beam splitter are demonstrated. The valley valve exploits the valley-momentum locking of the kink states and reaches an on/off ratio of 8 at zero magnetic field. A magnetic field enables a full-range tunable coherent beam splitter. These results pave a path to building a scalable, coherent quantum transportation network based on the kink states.

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一种谷阀和电子分束器

制作实用的谷电子学器件具有六边形晶格的二维材料，如石墨烯，在其能带结构中有两个不同的“谷”。谷电子学新兴领域的研究人员希望这些谷自由度可以作为信息载体被利用，但是制作谷电子学设备是很棘手的。李等人。在双层石墨烯的相反门控区域之间的边界上创建了手性谷霍尔态。然后，他们使用空间调制门控引导这些所谓的扭结状态通过他们的样本，展示了右转和左转以及谷阀功能。科学，这个问题 p。1149 双层石墨烯样品的空间调制门控控制手性谷霍尔电流的传播。开发超越硅技术的电子替代范式需要探索全新的物理机制，例如六角二维材料中的谷特定现象。我们在双层石墨烯中实现了弹道谷霍尔扭结状态，并在四扭结路由器设备中演示了门控电流传输。演示了波导、阀门和可调电子分束器的操作。谷阀利用扭结状态的谷动量锁定，并在零磁场下达到 8 的开/关比。磁场使全范围可调谐相干分束器成为可能。这些结果为构建基于扭结状态的可扩展、相干量子传输网络铺平了道路。例如六边形二维材料中的谷特定现象。我们在双层石墨烯中实现了弹道谷霍尔扭结状态，并在四扭结路由器设备中演示了门控电流传输。演示了波导、阀门和可调电子分束器的操作。谷阀利用扭结状态的谷动量锁定，并在零磁场下达到 8 的开/关比。磁场使全范围可调谐相干分束器成为可能。这些结果为构建基于扭结状态的可扩展、相干量子传输网络铺平了道路。例如六边形二维材料中的谷特定现象。我们在双层石墨烯中实现了弹道谷霍尔扭结状态，并在四扭结路由器设备中演示了门控电流传输。演示了波导、阀门和可调电子分束器的操作。谷阀利用扭结状态的谷动量锁定，并在零磁场下达到 8 的开/关比。磁场使全范围可调谐相干分束器成为可能。这些结果为构建基于扭结状态的可扩展、相干量子传输网络铺平了道路。演示了阀门和可调电子束分离器。谷阀利用扭结状态的谷动量锁定，并在零磁场下达到 8 的开/关比。磁场使全范围可调谐相干分束器成为可能。这些结果为构建基于扭结状态的可扩展、相干量子传输网络铺平了道路。演示了阀门和可调电子束分离器。谷阀利用扭结状态的谷动量锁定，并在零磁场下达到 8 的开/关比。磁场使全范围可调谐相干分束器成为可能。这些结果为构建基于扭结状态的可扩展、相干量子传输网络铺平了道路。